Volume

29.57 mL = 1 fluid ounce
473 mL = 1 pint
1 liter = 33.8 fluid ounces
3785 mL = 1 gallon
5 mL = 1 teaspoon
15 mL = 1 tablespoon or 1⁄2 fluid ounce

Weight

1 kilogram [kg] = 2.2 lbs
1 pound = 453.59 grams
1 ounce = 28.35 grams
1 gram = 15.432 grains
1 grain = 65 mg
1/2 grain = 32.4 mg
1/4 grain = 16.2 mg

Height

1 centimeter [cm] = 0.39 inches
1 inch = 2.54 cm
1 meter = 39.37 inches
1 micron = 1/1000 mm
Other useful measures
1 liter of water weighs 1 kg
1 mL of water weighs 1 gram